Scorching Heat Fuels ‘Cheatwave’: Sunlit Surge in Infidelity as Inhibitions Fade, Experts Warn

Heatwave Sparks Surge in Cheating as ‘Sundrunk’ Brits Lose Inhibitions
By Xantha Leatham, Executive Science Editor
Published: 16:17 BST, 11 July 2025 | Updated: 16:17 BST, 11 July 2025

As the UK braces for temperatures up to 32°C this weekend, experts warn of a "cheatwave"—a spike in infidelity linked to soaring heat. Data reveals a 58% surge in sign-ups to affair websites during recent heatwaves, with women aged 35–44 dominating new memberships.

Jessica Leoni, a relationship expert at IllicitEncounters.com, attributes this trend to "heatwave hedonism," where warm weather lowers inhibitions and mimics vacation behavior. "Sunshine strips away restraint," she explains. "People feel ‘sundrunk’—like they’re on holiday, even at home."

A poll of 1,000 affair site users found 66% felt "more impulsive" in the heat, while 55% claimed temperatures pushed them to act on longstanding desires. Last week’s peak of 34.7°C in London marked the year’s hottest day, coinciding with spikes in risky behavior.

Why Heat Fuels Infidelity
Leoni notes hormonal changes and a "holiday persona" contribute to poor decisions. Meanwhile, an amber health alert spans southern England, and hosepipe bans loom.

Research also links power dynamics to cheating. A Reichman University study found powerful individuals—who perceive themselves as more desirable—are likelier to stray. Professor Gurit Birnbaum explains, "They believe they have more options and feel less dependent on partners."

Facial Features and Infidelity
A Canadian study suggests face shape may predict cheating tendencies. Men and women with wider, shorter faces (high facial width-to-height ratio) reported stronger sex drives and openness to casual encounters. Square-faced individuals are often perceived as dominant or aggressive, traits tied to short-term mating.

As temperatures climb, experts urge caution: the combination of heat-induced impulsivity and opportunity could test even the strongest relationships.

Key Takeaways

• Heatwaves boost affair website traffic by 58%, driven by lowered inhibitions.
• Women aged 35–44 are most likely to join during spikes.
• Power imbalances and facial features may also influence cheating risks.

Stay vigilant—sunshine might feel liberating, but it could also rewrite relationship rules.